Compression method, compression device, and computer-readable recording medium

Abstract

A non-transitory computer-readable recording medium stores a compression program that causes a computer to execute a process. The process includes: detecting a matched data that matches a processing target data with a longest length among pieces of data, the pieces of data being extracted from a data sequence that is a compression target; acquiring an appearance frequency of a code corresponding to character data contained in the matched data when a data length of the matched data is smaller than a predetermined length; acquiring an appearance frequency of a code corresponding to the matched data when the data length of the match data is equal to or larger than the predetermined length; and compressing the data sequence using a compression code generated based on the acquired appearance frequency of the code.

What is claimed is: 
     
       1. A non-transitory computer-readable recording medium storing a compression program that causes a computer to execute a process comprising:
 detecting a matched data that matches a processing target data with a longest length among pieces of data, the pieces of data being extracted from a data sequence that is a compression target; 
 acquiring an appearance frequency of a code corresponding to character data contained in the matched data when a data length of the matched data is smaller than a predetermined length; 
 acquiring an appearance frequency of a code corresponding to the matched data when the data length of the matched data is equal to or larger than the predetermined length; and 
 compressing the data sequence using a compression code generated based on the acquired appearance frequency of the code. 
 
     
     
       2. The non-transitory computer-readable recording medium according to  claim 1 , wherein the compressing includes generating a tree based on a frequency calculated by adding up an appearance frequency of character data and an appearance frequency of length data that correspond to a same code. 
     
     
       3. The non-transitory computer-readable recording medium according to  claim 1 , wherein the compressing includes compressing the data sequence as the compression target using a tree in which a code corresponding to character data and length data is assigned to each leaf of a tree. 
     
     
       4. A compression method comprising:
 detecting a matched data that matches a processing target data with a longest length among pieces of data, the pieces of data being extracted from a data sequence that is a compression target; 
 acquiring an appearance frequency of a code corresponding to character data contained in the matched data when a data length of the matched data is smaller than a predetermined length; 
 acquiring an appearance frequency of a code corresponding to the matched data when the data length of the matched data is equal to or larger than the predetermined length; and 
 compressing the data sequence using a compression code generated based on the acquired appearance frequency of the code. 
 
     
     
       5. A compression device comprising:
 a processor configured to:
 detect a matched data that matches a processing target data with a longest length among pieces of data, the pieces of data being extracted from a data sequence that is a compression target; 
 acquire an appearance frequency of a code corresponding to character data contained in the matched data when a data length of the matched data is smaller than a predetermined length; 
 acquire an appearance frequency of a code corresponding to the matched data when the data length of the matched data is equal to or larger than the predetermined length; and 
 compress the data sequence using a compression code generated based on the acquired appearance frequency of the code.